The number in the "Order number"-column is the number we need if you want to order the part.
The number in the "OEM reference"-column is the "Original Equipment Manufacturer" number, the original part number.

From the Order number you can tell if it is an original or repro part: If the number begins with a letter it is a repro part. (usually a R for parts, an L for books, C for Colony kits, etc.)
Many items are listed without a price, this means they are in stock but you will have to ask for a price quote.